Cost, Healthcare Resource Utilization Greater in Patients with AATD with Liver, Lung Disease

Compared to patients with alpha-1 antitrypsin deficiency (AATD) alone, findings from a recent study suggest patients with AATD with liver and/or lung disease face greater all-cause costs and healthcare resource utilization.¹

The retrospective, observational analysis of linked administrative claims data and electronic medical records provides novel insight into the estimated incremental costs of AATD, liver disease, lung disease, or both liver and lung disease. Results point to increased healthcare resource utilization and healthcare costs per person-year (PPY) in the presence of liver and/or lung disease.¹

“Economic data on AATD-associated liver disease are sparse,” Charlie Strange, MD, professor of pulmonary and critical care medicine at the Medical University of South Carolina, and colleagues wrote.¹ “However, these data are an important contributor to the costs of hospitalization associated with metabolic dysfunction-associated genetic liver disease, and the considerable costs associated with transplantation with life-long immunosuppression.”

A genetic disease involving a lack of or abnormality in the production of alpha-1 protein, AATD can lead to both lung disease and liver disease. Alpha-1 antitrypsin is necessary to protect tissues in the body, particularly the lungs, so a lack of this protein can lead to lung disease while its build-up in the liver can also lead to liver disease.² However, little is known about the economic impact of AATD.

To assess all-cause and liver-associated healthcare resource utilization and costs among patients with AATD with liver disease and/or lung disease, investigators conducted a non-interventional, retrospective, observational analysis of linked administrative claims data and electronic medical records from the IQVIA PharMetrics Plus and IQVIA Ambulatory Electronic Medical Records databases from July 1, 2011, through January 31, 2022.¹

The aggregated IQVIA PharMetrics Plus database comprises adjudicated medical and pharmacy claims for more than 190 million unique patients with commercially managed health insurance across the US. The IQVIA Ambulatory Electronic Medical Records database comprises approximately 75 million patient records sourced from an ‘opt-in’ provider research network involving 40,000 physicians.¹

Patients were included if they had ≥ 1 inpatient or ≥ 2 outpatient medical claims ≥ 90 days apart with a diagnosis of AATD in the IQVIA PharMetrics Plus database, or with records indicating a protease inhibitor (Pi)*ZZ/Pi*MZ genotype in the IQVIA Ambulatory Electronic Medical Records database with linkage to IQVIA PharMetrics Plus. For a patient's identified continuous enrollment period, investigators assigned patient time to health states based on the initial encounter with a liver disease or lung disease diagnosis.¹

A unique index date was defined for each health state, and owing to the varying length of time in each health state, healthcare resource utilization and costs were calculated PPY as the total number of services or costs in a health state divided by the total length of follow-up in a health state.¹

Overall, 5136 adult and pediatric patients from the IQVIA PharMetrics Plus and IQVIA AEMR databases were analyzed. Investigators assigned patient follow-up time to the following health states: AATD only (n = 1804); AATD prior to liver or lung disease (n = 3291); AATD with liver disease (n = 877); AATD with lung disease (n = 2343); and AATD with liver and lung disease (n = 566). Among the overall cohort, 7 (0.1%) and 55 (1.1%) patients had a reported Pi*ZZ or Pi*MZ genotype, respectively, while the majority of patients in the overall cohort (98.8%) had no documented genotype.¹

Results showed all-cause and liver-associated healthcare resource utilization and costs were substantially increased following the onset of liver disease/lung disease and uniformly greatest in the AATD with liver and lung disease health state. All-cause cost PPY ranged from $11,877 in the absence of either liver or lung disease to US $74,015 in the presence of both liver disease and lung disease.¹

Among liver transplant recipients in the AATD with liver disease health state, investigators noted liver-associated total cost PPY was greater in patients 1-year post-transplantation ($461,752) than 1-year pre-transplantation ($87,329), driven by high inpatients costs 1-year post-transplantation ($428,492 vs $35,231). Of note, these figures were considerably higher than those observed among patients who did not receive a liver transplant (total cost PPY, $6845; inpatient cost, $2780).¹

In the AATD with lung disease and AATD with liver disease and lung disease health states, patients who received augmentation therapy had greater all-cause total costs PPY and lower liver-associated total costs PPY than their counterparts who did not receive augmentation therapy (AATD with lung disease, $124,545; n = 443; 1398.89 person-years vs $23,367; n = 1900; 5675.60 person-years) (AATD with liver disease and lung disease, $150,981; n = 76; 172.83 person-years vs $61,817; n = 490; 1090.52 person-years).¹

Investigators recognized several potential limitations to these findings, including the lack of generalizability to patients without commercially managed health insurance; the underrepresentation of older patients who are more likely to have AATD with liver disease and/or lung disease; the variable amounts of time which patients were followed for; and the inability to account for fibrosis, cirrhosis, or AATD genotype.¹

“To our knowledge, the estimated incremental costs of AATD, liver disease, lung disease or both liver and lung disease have not been published previously,” investigators concluded.¹ “In our study, HCRU and healthcare costs in patients with AATD were higher in the presence of liver and/or lung disease than in patients with AATD only or AATD prior to liver or lung disease.”

References:

1. ^{Hagiwara M, Divino V, Munnangi S, et al. Healthcare resource utilization and costs among patients with alpha-1 antitrypsin deficiency with liver and/or lung disease: a longitudinal retrospective study in the USA. J Comp Eff Res. 2024;13(6):e230186. doi:10.57264/cer-2023-0186}
2. ^{Cincinnati Children’s. Alpha-1 Antitrypsin Deficiency (AATD). January 2024. Accessed June 17, 2024. https://www.cincinnatichildrens.org/health/a/alpha-1-antitrypsin-deficiency}